You've driven through it many times. Ever wondered what's inside it? Bob Hazen went in and tweeted these photos while waiting to do his live reports about the Squirrel Hill Tunnel weekend closure on Pittsburgh's Action News 4 This Morning.

No work will occur during the July 4th holiday weekend until 10 p.m. Sunday, when there will be a single-lane closure outbound lasting until 6:30 a.m. Monday. One outbound lane will remain open during that time.

Photos: Take a peek inside the Squirrel Hill Tunnel

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Bob Hazen

Bob Hazen went inside the Squirrel Hill Tunnel and tweeted pictures while he had some time to spare between his live reports on Pittsburgh's Action News 4 This Morning.